Women get more colds than men, probably because they tend to have closer contact with children.

The common cold is much more frequent in winter months, a trend that is seen in all countries of the Northern Hemisphere. Rhinovirus, the most common cause, shows peaks of activity in late autumn and early spring. Colds caught in the summer months are more likely to be caused by other viruses, such as coronavirus, and para-influenza virus [Tolan and Nguyen, 2007]. So far there has no generally accepted explanation for the observed seasonality of the common cold.

It has been suggested that the increased rate of the cold in winter is due to people being in closer proximity indoors [Gwaltney, 1995], but this unlikely to account for the degree of difference seen, and is not universally accepted.

There is limited evidence that the traditional belief that chilling increases the likelihood of the cold may have some basis in reality [Johnson and Eccles, 2005].